Cab structure for a forestry swing machine



FIG. 1 is a front perspective view of a cab structure for a forestry swing machine showing an embodiment of our new design;

FIG. 2 is a front perspective view of a cab structure for a forestry swing machine showing another embodiment of our new design; and,

FIG. 3 is a front perspective view of a cab structure for a forestry swing machine showing another embodiment of our new design.

The broken line showing is for illustrative purposes only, and forms no part of the claimed design. 

The ornamental design for a cab structure for a forestry swing machine, as shown and described. 